Slice the tofu into 1cm thick pieces.
Pat the tofu dry with a kitchen towel to remove moisture.
Slice the onion, green onion, and chili pepper diagonally.
Mix together the seasonings (soy sauce, red pepper powder, minced garlic, sugar, sesame oil, water).
Heat oil in a pan and pan-fry the tofu until golden brown.
Place the vegetables on top of the tofu and pour the sauce over.
Simmer on medium-low heat until the sauce thickens.